[Duffy]

(02-01-2015, 02:23 PM)Island Chris Wrote: Following up on Roger, there is a M6+ quake on average every 2 or 3 days. Since many of these would be aftershocks of much larger quakes, then the actual dates of M6-7 quake occurrence would be less often.

I know Duffy was joking, but earthquakes/Earthwaves is a hobby for me also. I probably know less about Radon/ionosphere than Duffy, Brian, or Roger. My professional work is on faults and folds, including active ones, so I do know a fair amount about "seismotectonics".

It is really clear from his posts that Duffy has a scientific approach. It clearly contrasts with others who used to post here. On the other hand, time will tell over the next few years whether Duffy is willing to accept or at least consider well-supported critical comments that are made here. For example, that there are >100 M 6 quakes/year, and I think it is something like 18 M7+ quakes/year.

Chris

Hi all,
I've put something together here to hopefully help to understand what an EM signiture looks like in the Radio spectrum, and its possible use as a short span prediction tool for Earthquake detection. Included in this post are several examples of VLF transmission images to convey to others exactly what I'm looking for. We're still rubbing two stick together to make fire where I live, so please forgive any errors I may have made in the following presentation (you may want to grab a coffee first, it's a bit long!).

[attachment=47]

This image is a typical example of a plot screen, taken from a 5 day spectrogram recording, generated in Spectrum Lab. The times shown are in UT (universal time) and each hour is divided into 15 minute grid sections, with a recording rate of 10 seconds. on the left of the screen, you will see where the last day finished and the new day started, the time stamp shows this was recorded several days ago.

Each of the coloured traces represents transmission frequencies of shortwave broadcasts, Atomic clock syncronisation signals, and the majority are naval transmissions from across the globe. The most distinguishable feature in this image is the V shape in the white trace representing Iceland. VLF waves (very low frequency) propogate through what is termed the radio corridor by two methods, the ground wave and sky wave (D-layer). Propogation is stronger from the ground wave during daylight hours, because the D-layer in the lower atmosphere is less conductive. The D-layer however, relies on UV radiation to sustain itself, so when the sun sets, it deminishes and allows the sky wave to become the dominant propogator. As Dawn approaches, the D-layer begins to re-materialise, creating a battle for dominance between the ground and sky waves, resulting in each cancelling the other out, hence the trace drops to the bottom of the screen. As the Sun rises, the ground wave becomes the dominant force again, and signal strength starts to increase. So in effect, your witnessing a VLF sunrise in Iceland.

The most significant trace for our purposs is the thin red line at the bottom of the screen. This is the noise to ratio trace that records EMI (Electromagnetic interfearance) from natural or man made sources. In the 2 hour period shown, there are several lightning strikes, and some low energy Solar wind interactions. The cream trace representing North Dakota USA shows man made disruption at 10:28 UT, which continues into the Iceland trace above, this may indicate a high frequency transmission from the US, in the direction of Iceland (a radio telescope sending instruction to a satellite or probe etc).

Unless anyone has had previouse experience with spectrograms, its not expected for the smaller details to be understood, just as I could not extrapolate date from a seismograph, having never seen one before. However, an EM signal with possible tectonic origins is very distinguishable from other sources.

This plot screen is an example of how I see the data as it comes in, I then change some of the trace colours, and add a white background for printing purposess

[attachment=48]

This second image was recorded later the same day as image 1, and shows an increase of terrestrial and Solar activity in the noise line. The significance of this image is the similarity of signal ratio reduction in the white (Iceland) and cream (N Dakota) traces, they are loosing strength and dropping towards the bottom right of the image. I noted this effect several days ago in the Scotish borders and Norwegian traces, they could all be coincidental reductions in transmitter power, but I believe the D-layer above these regions has been contaminated by Radon gas (a phenomena mentioned in an earlier post). Radon is produced from radioactive decay of minerals in the Earths crust, it has a half-life of approximately 3.9 days, and is mostly associated with volcanic and tectonic activity. When Radon interacts with the D-layer it basically doubles the ionisation process, causing the radio ceiling to drop further (squeezing the coridoor, so to speak) As Iceland is volcanicaly active, and taking into account the 19th January when a mag 4.6 Earthquake struck in the Greenland sea, it's feasable that Radon seepage could be occuring

[attachment=49]

Show here is a portion of a recording taken on 5th February 2013, it's this recording that introduced me to the realms of Earthquakes in the first place, and the reason I wished to understand them. At the time this was taken, I had only been a SID monitorist for 4 months, and still at the early learning stage, hence the poor quality of the traces. Two weeks prior to this recording, I constructed an antenna of my own design, as the store bought antenna was not producing the results I'd expected. When this image appeared on my monitor, I believed it to be equipment malfunction, no problem was detected and Solar influences were ruled out as the cause. I knew there was some kind of electromagnetic element to this, but settled on a antenna glitch as this was the newest part of the system. The following morning (6th Feb) whilst having my coffee and watching the TV news bullitins, the news reporter announced that a Magnitude 8 Earthquake had taken place, near the Solomon Islands. It wasn't long before I realised the connection, and in my quest for answers, I found the Radon gas phenomenon. It's quite obvious from the image that something brought the radio ceiling crashing down at 11:05 UT, and remained this way untill 16:45 UT when normal recording resumed. So is this a mass release of Radon prior to Solomon?, I believe it is, there is nothing on the internet for comparison (that I could find), the whole recording is now framed, hanging on my wall, and titled "Day One". I recorded several of these in 2013, but this one is all that remains.

Now I would just like to add a side note, I don't want to spoil a good run here, and I've done my best to keep her out of it, but this may or may not have any relevance. I remember on this day, Mother-in-law was insistant on returning to the store with some wild bird food (anybody know where this is going?), she's a keen bird watcher with a couple of feed stations in the garden, and believed the store had sold her old stock as the birds hadn't appeared all day. Animal behaviourist may have theories on this, I'm a stick to the facts kind of guy, but you never know!.

[attachment=50]


I thought I would show a couple of images of other EMI phenomena, to give an example of some of the variables that have to be taken into consideration when trying to establish a link between EM signals and PQ signals (Possible Quake). This image is typical of how lightening leaves EM signatures in the noise line, each of these large peaks is a bolt of lightening making contact with the Earth, the storm past by my location 30km North. If you look at the gap in the strikes,just before 17:00 UT, you will notice above it a couple of trace lines with distinct curves, these were caused by an M1 class solar flare ionising the upper atmosphere, and counteracting the electrostatic energy released by the lightening, hence the gap.

[attachment=51]

I originally constructed the SID detector (Sudden Ionospheric Disturbance) to capture images of Solar activity, like the example shown here. The first indication of a CME from the Sun (coronal Mass Ejection) is the arrival of X-ray radiation impacting the Earths magnetic field. This has the effect of raising and lowering the radio ceiling as shown in the image, you'll notice however, the noise line has suffered little or no disruption. The pale Green trace represents France, and the time shows it was basically High Noon in Europe. The Solar classification for these flare impacts, from the left are M1.4, C8.3 and M1.3, as a rough guide in Eathquake terminology, Mag 7.3, Mag 6 and Mag 7.1 (just examples, incase the calculators start coming out). Coronal material arrives at Earth a couple of days later, producing the aurora's over the pole's, and shows as a proton/electron storm (Solar wind) in the noise line.

To be continued in next post

Duffy